The calculated distance (air line) between Đồng Xoài and Phnom Penh is approximately 133 miles respectively 214 kilometers.
By car or train, the actual journey to Phnom Penh is certainly longer, as only the direct route (as the crow flies) between Đồng Xoài and Phnom Penh has been calculated here.
Air line (approximately)
214 kilometers
116 nautical miles